Polypyrrole has been known as an organic conductive ultrathin film. A conductive polypyrrole can be formed by the electrolytic polymerization of a pyrrole derivative. This conductive polypyrrole has been applied to electronic devices such as diodes and field effect transistors, and to optoelectronic devices including electrochromic elements, optical memory elements and the like. Due to the recent miniaturization of devices, conductive films are consequently required to be made thinner. It has also been a goal to develop a pyrrole derivative which can form a conductive ultrathin film much more easily and consistently than other materials.
Forming a conductive ultrathin film on a substrate surface by using a pyrrole derivative can be done by the following procedure:
providing a monomer by bonding long-chain organic groups to pyrrole; PA1 forming a monomer monomolecular film on a substrate surface by the Langmuir-Blodgett method (LB method); and PA1 polymerizing the film on the substrate surface.
However, in the case of this conventional pyrrole derivative, the monomolecular film is only physically adsorbed to the substrate even by the LB method. The monomer is also likely to be evaporated or scattered before or during the polymerization process. Therefore, it has been difficult to form a fully optimal conductive ultrathin film.